scholarly journals Influence of Specimen Thickness on the Acquisition of Al6061-T6 Material Properties Using SHPB and Verified by FEM

Materials ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 205
Author(s):  
Yeon-Bok Kim ◽  
Jeong Kim
Keyword(s):  
Strain Rate ◽  
Material Properties ◽  
High Strain ◽  
Split Hopkinson Pressure Bar ◽  
Applied Pressure ◽  
Specimen Thickness ◽  
Hopkinson Pressure Bar ◽  
Shpb Test ◽  
S Curve ◽  
Thickness Variations

The Split-Hopkinson pressure bar (SHPB), which is used for acquiring material properties at high strain rates (102–104 s−1), requires proper specimen size selection. Under the same applied pressure, an increased S-S curve is obtained as the thickness of the specimen decreases. In this study, 1.5 t, 2.0 t, 3.0 t, 5.0 t, and 7.0 t specimens of Al6061-T6 material were tested under 1.0 bar to understand the influence of specimen thickness on the acquisition of material properties. To grasp the behavior of the SHPB test in real time, Finite Element Method (FEM) was performed using the LS-DYNA program. During the SHPB test, the impedance is increased due to the variation in the specimen area. Because of the influence of impedance, the transmitted pulse increases, and the reflected pulse decreases. As a result, the specimen is deformed in the high-strain rate region, and the S-S curve is increased as the thickness decreases. In addition, by performing the test under different pressure conditions that created similar strain rate regions, the material properties remained constant with thickness variations.

Tension and Compression Behavior of Pre-Stressed Steel Strands at High Strain Rate

2011 ◽  
Vol 82 ◽  
pp. 154-159 ◽  
Author(s):  
Anatoly M. Bragov ◽  
Ezio Cadoni ◽  
Alexandr Yu. Konstantinov ◽  
Andrey K. Lomunov
Keyword(s):  
High Strain Rate ◽  
Strain Rate ◽  
High Strain ◽  
Split Hopkinson Pressure Bar ◽  
High Strength ◽  
Gauge Length ◽  
Hopkinson Pressure Bar ◽  
Dog Bone ◽  
Tension And Compression ◽  
Set Up

In this paper is described the mechanical characterization at high strain rate of the high strength steel usually adopted for strands. The experimental set-up used for high strain rates testing: in tension and compression was the Split Hopkinson Pressure Bar installed in the Laboratory of Dynamic Investigation of Materials in Nizhny Novgorod. The high strain rate data in tension was obtained with dog-bone shaped specimens of 3mm in diameter and 5mm of gauge length. The specimens were screwed between incident and transmitter bars. The specimens used in compression was a cylinder of 3mm in diameter and 5mm in length. The enhancement of the mechanical properties is quite limited compared the usual reinforcing steels.

Dynamic Behaviors of near β-Type Ti-5Al-5Mo-5V-3Cr Titanium Alloys under High Strain Rate

2015 ◽  
Vol 816 ◽  
pp. 795-803
Author(s):  
Yan Ling Wang ◽  
Song Xiao Hui ◽  
Wen Jun Ye ◽  
Rui Liu
Keyword(s):  
Strain Rate ◽  
Titanium Alloys ◽  
High Strain ◽  
Split Hopkinson Pressure Bar ◽  
Failure Behavior ◽  
Hopkinson Pressure Bar ◽  
Fracture Failure ◽  
Split Hopkinson ◽  
Pressure Bar ◽  
Dynamic Loading Conditions

The mechanical properties and fracture failure behavior of the near β-type Ti-5Al-5Mo-5V-3Cr-X (X = 1Fe or 1Zr) titanium alloys were studied by Split Hopkinson Pressure Bar (SHPB) experiment under the dynamic loading conditions at a strain rate of 1.5 × 103 s-1–5.0 × 103 s-1. Results showed that the SHPB specimen fractured in the direction of maximum shearing stress at an angle of 45° with the compression axis. The fracture surface revealed the shear and tension zones with cleavage steps and parabolic dimples. Severe early unloading was observed on the Ti-5553 alloy under a strain rate of 4,900 s-1 loading condition, and the dynamic property of the Ti-55531Zr alloy was proved to be the optimal.

scholarly journals High Strain Rate Deformation Behavior and Recrystallization of Alloy 718

2021 ◽  
Author(s):  
Marie Anna Moretti ◽  
Biswajit Dalai ◽  
Paul Åkerström ◽  
Corinne Arvieu ◽  
Dimitri Jacquin ◽  
...  
Keyword(s):  
Strain Rate ◽  
Deformation Behavior ◽  
High Strain ◽  
Split Hopkinson Pressure Bar ◽  
Optical Microscope ◽  
Electron Back Scatter Diffraction ◽  
Alloy 718 ◽  
Compression Tests ◽  
Hopkinson Pressure Bar ◽  
Recrystallized Grain Size

AbstractTo study the deformation behavior and recrystallization of alloy 718 in annealed and aged state, compression tests were performed using Split-Hopkinson pressure bar (SHPB) at high strain rates (1000 to 3000 s−1), for temperatures between 20 $$^\circ $$ ∘ C and 1100 $$^\circ $$ ∘ C (293 K to 1373 K). Optical microscope (OM) and electron back-scatter diffraction (EBSD) technique were employed to characterize the microstructural evolution of the alloy. The stress–strain curves show that the flow stress level decreases with increasing temperature and decreasing strain rate. In addition, up to 1000 $$^\circ $$ ∘ C, the aged material presents higher strength and is more resistant to deformation than the annealed one, with a yield strength around 200 MPa higher. For both states, dynamic and meta-dynamic recrystallization occurred when the material is deformed at 1000 $$^\circ $$ ∘ C and 1100 $$^\circ $$ ∘ C, leading to a refinement of the microstructure. As necklace structures were identified, discontinuous recrystallization is considered to be the main recrystallization mechanism. The recrystallization kinetics is faster for higher temperatures, as the fraction of recrystallized grains is higher and the average recrystallized grain size is larger after deformation at 1100 $$^\circ $$ ∘ C than after deformation at 1000 $$^\circ $$ ∘ C.

A Dynamic Mechanical Analysis of T2 Copper at High Strain Rates

2019 ◽  
Vol 812 ◽  
pp. 38-44
Author(s):  
Shuai Chen ◽  
Wen Bin Li ◽  
Xiao Ming Wang ◽  
Wen Jin Yao
Keyword(s):  
Yield Strength ◽  
Strain Rate ◽  
High Strain ◽  
Split Hopkinson Pressure Bar ◽  
Pure Copper ◽  
Dislocation Slip ◽  
Strain Rates ◽  
High Strain Rates ◽  
Stress Strain ◽  
Shpb Test

This work compares the pure copper (T2 copper)’s stress-strain relationship at different strain rates in the uni-axial tension test and Split Hopkinson Pressure Bar (SHPB) test. Small samples were utilized in the high strain rate SHPB test in which the accuracy was modified by numerical simulation. The experimental results showed that the T2 copper’s yield strength at high strain rates largely outweighed the quasi static yield strength. The flow stress in the stress-strain curves at different strain rates appeared to be divergent and increased with the increase in strain rates, showing great strain strengthening and strain rate hardening effects. Metallographic observation showed that the microstructure of T2 copper changed from equiaxed grains to twins and the interaction between the dislocation slip zone grain boundary and twins promoted the super plasticity distortion in T2 copper.

scholarly journals High Strain-Rate Compressive Properties of Carbon/Epoxy Laminated Composites – Effects of loading direction and temperature

2018 ◽  
Vol 183 ◽  
pp. 02011
Author(s):  
Kenji Nakai ◽  
Tsubasa Fukushima ◽  
Takashi Yokoyama ◽  
Kazuo Arakawa
Keyword(s):  
High Strain Rate ◽  
Strain Rate ◽  
Elevated Temperatures ◽  
High Strain ◽  
Split Hopkinson Pressure Bar ◽  
Slenderness Ratio ◽  
Testing Machine ◽  
Negative Temperature ◽  
Hopkinson Pressure Bar ◽  
Instron Testing Machine

The high strain-rate compressive characteristics of a cross-ply carbon/epoxy laminated composite in the three principal material directions or fibre (1-), in-plane transverse (2-) and throughthickness (3-) directions are investigated on the conventional split Hopkinson pressure bar (SHPB) over a range of temperatures between 20 and 80 °C. A nearly 10 mm thick cross-ply carbon/epoxy composite laminate fabricated using vacuum assisted resin transfer molding (VaRTM) was tested. Cylindrical specimens with a slenderness ratio (= length/diameter) of 0.5 are used in high strain-rate tests, and those with the slenderness ratios of 1.0 and 1.5 are used in low and intermediate strain-rate tests. The uniaxial compressive stress-strain curves up to failure at quasi-static and intermediate strain rates are measured on an Instron testing machine at elevated temperatures. A pair of steel rings is attached to both ends of the cylindrical specimens to prevent premature end crushing in the 1-and 2-direction tests on the Instron testing machine. It is shown that the ultimate compressive strength (or failure stress) exhibits positive strainrate effects and negative temperature ones over a strain-rate range of 10–3 to 103/s and a temperature range of 20 to 80 °C in the three principal material directions.

High Strain Rate Response of Rocks Under Dynamic Loading Using Split Hopkinson Pressure Bar

2017 ◽  
Vol 36 (1) ◽  
pp. 531-549 ◽  
Author(s):  
Sunita Mishra ◽  
Hemant Meena ◽  
Vedant Parashar ◽  
Anuradha Khetwal ◽  
Tanusree Chakraborty ◽  
...  
Keyword(s):  
High Strain Rate ◽  
Strain Rate ◽  
Dynamic Loading ◽  
High Strain ◽  
Split Hopkinson Pressure Bar ◽  
Hopkinson Pressure Bar ◽  
Split Hopkinson ◽  
Pressure Bar
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